From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54752) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YpxQs-00057e-2q for qemu-devel@nongnu.org; Wed, 06 May 2015 07:24:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YpxQn-0003Qg-O4 for qemu-devel@nongnu.org; Wed, 06 May 2015 07:24:05 -0400 From: Fam Zheng Date: Wed, 6 May 2015 19:23:34 +0800 Message-Id: <1430911419-8256-3-git-send-email-famz@redhat.com> In-Reply-To: <1430911419-8256-1-git-send-email-famz@redhat.com> References: <1430911419-8256-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [RFC PATCH 2/7] block: Block "device IO" during bdrv_drain and bdrv_drain_all List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , qemu-block@nongnu.org, jcody@redhat.com, armbru@redhat.com, mreitz@redhat.com, Stefan Hajnoczi , pbonzini@redhat.com We don't want new requests from guest, so block the operation around the nested poll. Signed-off-by: Fam Zheng --- block/io.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/block/io.c b/block/io.c index 1ce62c4..d369de3 100644 --- a/block/io.c +++ b/block/io.c @@ -289,9 +289,15 @@ static bool bdrv_drain_one(BlockDriverState *bs) */ void bdrv_drain(BlockDriverState *bs) { + Error *blocker = NULL; + + error_setg(&blocker, "bdrv_drain in progress"); + bdrv_op_block(bs, BLOCK_OP_TYPE_DEVICE_IO, blocker); while (bdrv_drain_one(bs)) { /* Keep iterating */ } + bdrv_op_unblock(bs, BLOCK_OP_TYPE_DEVICE_IO, blocker); + error_free(blocker); } /* @@ -311,6 +317,9 @@ void bdrv_drain_all(void) /* Always run first iteration so any pending completion BHs run */ bool busy = true; BlockDriverState *bs = NULL; + Error *blocker = NULL; + + error_setg(&blocker, "bdrv_drain_all in progress"); while ((bs = bdrv_next(bs))) { AioContext *aio_context = bdrv_get_aio_context(bs); @@ -319,6 +328,7 @@ void bdrv_drain_all(void) if (bs->job) { block_job_pause(bs->job); } + bdrv_op_block(bs, BLOCK_OP_TYPE_DEVICE_IO, blocker); aio_context_release(aio_context); } @@ -343,8 +353,10 @@ void bdrv_drain_all(void) if (bs->job) { block_job_resume(bs->job); } + bdrv_op_unblock(bs, BLOCK_OP_TYPE_DEVICE_IO, blocker); aio_context_release(aio_context); } + error_free(blocker); } /** -- 1.9.3